Plaster-board.



No. 897,158. f PATENTED AUG. 25, 1908. J. J. RYAN.

PLASTER BOARD.

APPLICATION TILED MAR.21, 1907.

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WWMWW W/TNESSES INVENTOH ATTORNEYS UNITED STATES PATENT Trina.

JOHN J. RYAN, OF

NEW YORK, N. Y.

PLASTER-BOARD.

Application filed March 21,

To all whom it may concern:

Be it known that I, JOHN J. RYAN, a citizen of the United States, and a resident of the city of New York, borough of Manhattan, in the county and State of New York, have invented a new and useful Im rovement in Plaster-Boards, of which the ollowing is a full, clear, and exact description.

The purpose of the invention is to provide a plaster board of simple yet effective construction, the outer face whereof is fire-proof and semiplastic, enabling a nail to be driven through the same to a point below or within the fire-proof semi-plastic material, so that the said semi-plastic material may be troweled hard and smooth when desired.

Another purpose of the invention is to provide a plaster board adapted for use in the construction of ceilings, side walls or partitions, and which is of durable and economic construction, and which when cast is bonded together from surface to surface.

Another purpose of the invention is to cast one face of the board rough or with corrugations, so that a coat of mortar can be applied to said surface.

The invention consists in the novel construction and combination of the several parts as will be hereinafter fully set forth and pointed out in the claims.

Reference is to be had to the accompanying drawings forming a partof this specification, in which similar characters of reference indicate corresponding parts in both figures. Figure 1 is a erspectlve view of one of the boards, parts eing broken away to illustrate the construction thereof; and Fig. 2 is a vertical section through a portion. of the board.

In the construction of the board, a suit able mold is em loyed, and liquid plaster of paris is poured therein to form an outer layer 10, and in casting this layer, which constitutes one of the sections of the board, corrugations 11 are produced in itsouter face, or said outer face 1s roughened to provide a sur- Specification of Letters Patent.

face to which a finishing coat of plaster will Patented Aug. 25, 1908. 1907. Serial No. 363,644.

key or cling. A sheet 12 of coarse burlap is now placed upon the inner face of the layer 10 while in a plastic or semi-plastic state, and. liquid plaster is poured upon this burlap sheet 12 producing a second laster layer 13, then a second sheet 14 of bur ap is bonded to the second plasterlayer 13. These successive layers of plaster and burlap may be of any desired number according to the needed thickness of the board, but what is generally the outer face of the board, or that opposite the plaster. or corrugated space, is formed of asbestos so as to render this portion of the board fire-proof. To -that end a layer 15 of asbestos is applied to the burlap sheet 4 the asbestos being mixed with a suitable diluent such as cement, so that the mixture is semiliquid, or so that it will bond with the said sheet 14 of burlap. The asbestos may be so repared that it will become hard, or so that 1t will remain comparatively soft or semiliquid for a reasonable length of time, enabling the head of a nail to be driven beneath the surface and the o ening thus formed close to present a smoot even surface. The plastic surface of the asbestos layer can be troweled to a smooth hard surface. It will be observed that there is a continuous keybond from surface to surface of the board, a bond existing between all the material employed.

Having thus described my invention, I claim as new and desire to secure by Letters Patent A plaster board comprising a .filling of plaster of aris having one of its faces corrugated, and the other covered with a sheet of burlap, a sheet of burlap intermediate the faces of theplaster paris, and a layer of asbestoson the outer sheet of burlap.

In testimony whereof I have signed my name to this specification in the presence 'of two subscribing Witnesses.

JOHN J. RYAN. Witnesses:

J. FRED ACKER, JOHN P. DAVIS. 

